It is challenging for depressed adolescents and their families to access specialized mental health services. A viable option is delivering treatment in the primary care clinic (PCC) setting; however, few effective models are currently available. The overall aim of this study is to assess in the pediatric PCC, the preliminary acceptability and feasibility of a novel collaborative stepped care model of treatment for depressed adolescents and study protocol. Interpersonal Psychotherapy for adolescents (IPT-A) is a guideline based treatment with established efficacy focusing on reducing depression symptoms and current interpersonal problems associated with depression. This stepped care model (SCIPT-A) first delivers a low intensity 6 session plus two parent session adaptation called Brief IPT-A (BIPT-A), a treatment designed for mild to moderate adolescent depression with impairment. The second phase in the model is for adolescents with persistent depressive symptoms who will receive 8 more sessions of IPT-A in combination with the addition of an antidepressant. The social worker clinicians (SW) currently employed in the PCC will be trained to deliver the BIPT-A and in the second phase, the pediatrician will provide the medication treatment in collaboration with the SW clinician continuing to provide IPT-A. Fifty adolescents identified by their primary care pediatrician and meeting criteria for DSM-IV major depression, dysthymic disorder, or depression, not otherwise specified will be randomized to receive either treatment as usual (TAU) or the SCIPT-A model of stepped collaborative depression care in the PCC for 16 weeks.TAU consists of pediatrician referral of depressed adolescents to either a psychologist, social worker or child psychiatrist within the clinic or to another mental health agency in the community. All adolescents will be administered clinical interviews and self-report questionnaires during the 16 week protocol to assess treatment acceptability, feasibility, safety and preliminary change in symptoms. The project will provide information concerning the feasibility and acceptability of this treatment model for adolescent depression delivered by pediatricians and social work clinicians in pediatric primary care practice.